1. Atomic Structure Chem Quest Protons, Neutrons, and Electrons

2. Curriculum Big Idea: Changes in matter are accompanied by changes in energy. Concept: Isotopes are atoms of the same element with different numbers of neutrons. PA Standard: “Identify the major components (protons, neutrons, and electrons) of the nuclear atom, and explain how they interact.”

3. Today’s Agenda Opener: What subatomic particles have we learned about so far? What are their charges, and where are they located? Go over Chem Quest: Atomic Structure POGIL (see handout) Review Powerpoint on subatomic particles and atomic structure Closure: What is a neutron? What is an isotope? Take Home Assignment: 4.3 Section Assessment (page 119 in the big red book) to be checked tomorrow

4. Atom: the smallest particle of an element that retains its identity in a chemical reaction

5. Today’s Chemistry Word: The Atomic Nucleus Core of the atom Small Dense Positively charged Composed of protons (+) and neutrons (0)

6. Atomic Number The whole numbers in the blocks of the periodic table The number of protons in one atom of a given element The number of electrons in a NEUTRAL atom of a given element Every element has a different number of protons.

7. Mass Number The total number of protons and neutrons in an atom of a given element Round the atomic masses on the periodic table. # neutrons = mass number – atomic number

8. Protons, Neutrons, Electrons

9. Isotopes of an Element have different numbers of neutrons, so they have different masses. Example: neon-20, neon-21, and neon-22 are three isotopes of neon, a gaseous element used in lighted signs.

10. Isotopes of Hydrogen

11. also called… Hydrogen-1 Hydrogen-2 Hydrogen-3

12. Atomic Mass atomic mass unit (amu): one twelfth of the mass of a carbon-12 atom. Example: helium-4 has about one-third the mass of a carbon-12 atom Example: nickel-60 has about five times the mass of a carbon-12 atom.